The present invention relates to a prime mover arrangement comprising an internal combustion engine for driving a first shaft and a steam engine which is connected to the first shaft by means of a clutch arrangement for driving a second shaft. Furthermore, means which interact with the clutch arrangement are arranged between the first shaft and the second shaft in order to transmit a rotary movement of the second shaft to the first shaft in a first operating mode and to allow a freewheel between the first shaft and the second shaft in a second operating mode.
The field of application of the present invention extends to a drive technology for motor vehicles, in particular a drive technology which includes an internal combustion engine and a steam engine for supporting the internal combustion engine.
The reduction of fuel consumption is of major importance in the development of internal combustion engines. Internal combustion engines convert a portion of the chemical energy of the fuel into mechanical energy for the purpose of driving motor vehicles. In the process, a large portion of the chemical energy is released as waste heat which is discharged in an unused state by the cooling system or in the exhaust gas of the internal combustion engine. In order to use this thermal energy, it is conceivable for the internal combustion engine to be coupled to a steam engine. In so doing, the thermal energy from the internal combustion engine is used to generate steam which is expanded in an expansion machine and consequently provides further energy which can be used to the drive the vehicle.
In particular, a combination of an internal combustion engine with a steam engine is suited for waste heat utilization in a commercial vehicle. This results from the fact that the internal combustion engine has to deliver a great deal of power in this case, and therefore a large amount of thermal energy is available for generating steam.
On the basis of the generally know prior art, it has been shown that the connection of the steam engine to the internal combustion is possible via a rigid coupling. In this way, the internal combustion engine already carries along the steam engine from the start-up of the former although there is still not a sufficient amount of steam pressure available for the steam engine. As a result, the disadvantage arises that the efficiency of the total system is reduced commensurate with the friction of the steam engine especially during start-up of the internal combustion engine and as long as said internal combustion engine only moderately generates heat.
It is furthermore known that the steam engine and the internal combustion engine are connected to one another via an intermediate free-wheel coupling. As a result, the internal combustion engine can rotate freely if there is not a sufficient amount of steam pressure available for the steam engine. In this case, the internal combustion engine does not have to overcome the additional friction of the steam engine. The disadvantage of this solution is that the combustion engine no longer carries the steam engine along, whereby the steam engine can possibly no longer independently start up due to the unfavorable standstill position thereof.
The German patent application DE 10 2010 031 498 A1 discloses an electromagnetic clutch which connects a steam engine to an internal combustion engine. In this case, a first shaft can be driven by the steam engine and a second shaft by the internal combustion engine. In addition an intermediate wheel is connected to the first shaft and a clutch bell is connected at least indirectly to the second shaft, wherein a free wheel is disposed between the intermediate wheel and clutch bell. The free wheel performs the task of transmitting the rotary movement of the intermediate wheel that is connected to the first shaft to the clutch bell and further of enabling a freewheel of the clutch with respect to the intermediate wheel. A frictional force or a form fit can be generated at least indirectly between the intermediate wheel and the clutch bell by means of an electromagnetic actuating force which is released by activating an electromagnet by means of a controller.